Taxonomic treatment of Abrahamia Randrian. & Lowry, a new genus of Anacardiaceae BOISSIERA from Madagascar Armand RANDRIANASOLO, Porter P. LOWRY II & George E. SCHATZ 71 BOISSIERA vol.71 Director Pierre-André Loizeau Editor-in-chief Martin W. Callmander Guest editor of Patrick Perret this volume Graphic Design Matthieu Berthod Author instructions for www.ville-ge.ch/cjb/publications_boissiera.php manuscript submissions Boissiera 71 was published on 27 December 2017 © CONSERVATOIRE ET JARDIN BOTANIQUES DE LA VILLE DE GENÈVE BOISSIERA Systematic Botany Monographs vol.71 Boissiera is indexed in: BIOSIS ® ISSN 0373-2975 / ISBN 978-2-8277-0087-5 Taxonomic treatment of Abrahamia Randrian. & Lowry, a new genus of Anacardiaceae from Madagascar Armand Randrianasolo Porter P. Lowry II George E. Schatz Addresses of the authors AR William L. Brown Center, Missouri Botanical Garden, P.O. Box 299, St. Louis, MO, 63166-0299, U.S.A. [email protected] PPL Africa and Madagascar Program, Missouri Botanical Garden, P.O. Box 299, St. Louis, MO, 63166-0299, U.S.A. Institut de Systématique, Evolution, Biodiversité (ISYEB), UMR 7205, Centre national de la Recherche scientifique/Muséum national d’Histoire naturelle/École pratique des Hautes Etudes, Université Pierre et Marie Curie, Sorbonne Universités, C.P. 39, 57 rue Cuvier, 75231 Paris CEDEX 05, France. GES Africa and Madagascar Program, Missouri Botanical Garden, P.O. Box 299, St. Louis, MO, 63166-0299, U.S.A. Taxonomic treatment of Abrahamia (Anacardiaceae) 7 Abstract he Malagasy endemic genus Abrahamia Randrian. & Lowry (Anacardiaceae) is T described and a taxonomic revision is presented in which 34 species are recog- nized, including 19 that are described as new. The previously known taxa from Mad- agascar have historically been treated in the genus Protorhus Engl. along with the type species from southern Africa, Protorhus longifolia (Bernh.) Engl. However, recent mor- phological and molecular phylogenetic studies have shown that the African species is more closely related to Ozoroa Delile and the Malagasy taxa comprise a distinct clade. Therefore the Malagasy taxa could no longer be accommodated in Protorhus, necessi- tating the description a new genus, described as Abrahamia. In the present revision, species of Abrahamia are recognized and distinguished from one another on the basis of morphological characters, primarily of the leaves, inflorescences, flowers and fruits, in combination with eco-geographic features. A total of 15 new combinations are made for taxa from Madagascar previously placed in Protorhus, and lectotypes are designated for 11 names. A key to the species is provide in English and French, and a full description is presented for each species, along with a list of material examined and a distribution map; an illustration is also included for each of the new species. Preliminary conserva- tion assessments following the IUCN Red List criteria indicate that 17 species, repre- senting 50% of the total, are threatened, of which 5 are considered “Endangered” [EN] and 12 “Vulnerable” [VU]. Résumé e genre Abrahamia Randrian. & Lowry (Anacardiaceae), endémique de Madagascar, L est décrit et une révision taxonomique est proposée avec 34 espèces reconnues, dont 19 sont nouvellement décrites. Les espèces précédemment décrites ont été jusqu’alors attribuées au genre Protorhus Engl., qui a pour espèce type, Protorhus longifolia (Bernh.) Engl., d’Afrique australe. Des études morphologiques et de phylogénie moléculaire récentes ont montré que l’espèce africaine est plus proche du genre Ozoroa Delile. Les représentants malgaches appartiennent à un clade distinct et donc ne peuvent plus être inclus dans Protorhus, nécessitant la description d’un nouveau genre, décrit ici sous le nom Abrahamia. Dans le cadre de la présente révision, les espèces d’Abrahamia sont décrites et distinguées les unes des autres à partir des caractères morphologiques, prin- cipalement des feuilles, des inflorescences, des fleurs et des fruits, en combinaison avec des caractères éco-géographiques. Un total de 15 combinaisons nouvelles sont faites pour les taxons de Madagascar précédemment placés dans Protorhus et des lectotypes sont désignés pour 11 noms. Une clé d’identification des espèces est fournie en anglais et en français, et une description complète est présentée pour chaque espèce, accom- pagnée d’une liste des échantillons examinés et d’une carte de distribution. Une illus- tration est également proposée pour chacune des nouvelles espèces. Une évaluation provisoire du statut de conservation des espèces suivant les critères de la Liste Rouge de l’UICN indique que 17 espèces, soit 50% du total, sont menacées, dont 5 sont considé- rées comme “En Danger” [EN] et 12 comme “Vulnérables” [VU]. Keywords ANACARDIACEAE – Abrahamia – Protorhus – Madagascar – Conservation – New Species 8 Boissiera 71 Introduction nacardiaceae are a moderately sized family of c. 800 species belonging to 81 cur- A rently recognized genera (PELL et al., 2011). Widely known for economically important plants such as cashew nuts and mangos, the family is most diverse in humid tropical regions, especially in Asia, South America and Africa, although some members occur in temperate areas. Anacardiaceae are also well represented in Madagascar, where 14 native genera and an estimated total of 94 species are found (MADAGASCAR CATALOGUE, 2017). The family was treated in the Flore de Madagascar et des Comores by PERRIER DE LA BÂTHIE (1946; see also PERRIER DE LA BÂTHIE, 1944), who recognized a total of just 38 spe- cies in 13 genera. This remained the only available treatment for more than five decades until the first author began a series of investigations aimed at updating the taxonomy of the entire family in Madagascar. Since then the amount of available herbarium material has grown tremendously, primarily through the efforts of Madagascar’s Service Forestier during the 1960s and 70s, and more recently from field work carried out by staff of the Missouri Botanical Garden and other research institutions starting in the 1970s. This has provided the basis for recent revisions of several genera, including Campnosperma Thwaites (RANDRIANASOLO & MILLER, 1998), Micronychia Oliv. (RANDRIANASOLO, 2000; RANDRIANASOLO & LOWRY, 2009), and Operculicarya H. Perrier (RANDRIANASOLO & LOWRY, 2006), along with the description of one new genus, Poupartiopsis Capuron ex J.D. Mitch. & Daly (MITCHELL et al., 2006) and new species in several genera, viz. Campno- sperma (RANDRIANASOLO & LOWRY, 2004), Operculicarya (RANDRIANASOLO & LOWRY, 2015), Poupartia Comm. ex Juss. (RANDRIANASOLO & MILLER, 1999), and Spondias L. (MITCHELL et al., 2012). Among the genera of Anacardiaceae present in Madagascar that remain to be revised, the largest comprises species long referred to the genus Protorhus Engl. This genus, described 135 years ago (ENGLER, 1881), was originally circumscribed to include eight species, one of which, P. longifolia (Bernh.) Engl., occurs in southern Africa and the remainder in Madagascar. Several decades later a second African species, P. namaquensis Sprague, was added (SPRAGUE, 1913) but was later transferred to Ozoroa Delile by VON TEICHMAN & VAN WYK (1994). PERRIER DE LA BÂTHIE (1944, 1946) described 8 new species from Madagascar, bringing the total number for the island to 15, and more recently RANDRIANASOLO (1998) recognized a total of 19 Malagasy species. While Madagascar has been regarded as the center of diversity of Protorhus (VON TEICHMAN, 1991a, 1991b; VON TEICHMAN & VAN WYK, 1994, 1996; RANDRIANASOLO, 1998), questions have been raised regarding whether the single African species should be treated as belonging to the same genus as the species present in Madagascar (VON TEICH- MAN, 1991a, 1991b; RANDRIANASOLO, 1998; PELL, 2004). Several striking morphologi- cal differences distinguish the taxa from these two areas, especially fruit characters. In particular, Malagasy Protorhus have ellipsoidal, symmetrical fruits with ruminate seeds and inseparable cotyledons (with the exception of one species), whereas the fruits of P. longifolia are ovoid to oblong and distinctly asymmetrical, with non-ruminate seeds and separable cotyledons. In a recent molecular phylogenetic study, PELL et al. (2008) tested the monophyly of Protorhus and confirmed that the genus, as historically circum- scribed, indeed comprises two distinct clades, one containing all 11 taxa from Mada- Taxonomic treatment of Abrahamia (Anacardiaceae) 9 gascar included in their sample, which is sister to Heeria argentea (Thunb.) Meisn. and Micronychia macrophylla H. Perrier (the only representatives sampled of these genera of 1 and 10 species, respectively), and another in which Protorhus longifolia from Africa is sister to the tropical African species Ozoroa insignis Delile, the only sampled member of this genus of c. 40 species (KOKWARO, 1986). While ENGLER (1881) did not indicate a type when he described Protorhus, 70 years later PHILLIPS (1951) designated P. longifolia as the lectotype. In light of the results of the molecular phylogenetic work of PELL et al. (2008), Protorhus, as previously circum- scribed, is polyphyletic and the name thus cannot be applied to the Malagasy species. As no other generic name is available for the members of the clade comprising species in Madagascar, it must therefore be recognized as a new genus. In the present study we for- mally describe Abrahamia Randrian. & Lowry to accommodate these species and pro- vide a comprehensive taxonomic revision